为了研究三峡调蓄过渡期长江河口地区秋季滨海滨江土壤的盐渍化状况,进行土样采集和盐分组成测定,利用统计分析软件对区域土壤盐渍化类型和特点进行主成分分析,对区域土壤盐分剖面类型进行聚类分析。分析结果表明:三峡调蓄过渡期河口地区秋季土壤以盐化潮土为主,阳离子组成Na^+为主,阴离子组成SO4^2-型略多于Cl^-型,土壤剖面盐分以上升积聚为主,盐分积聚既呈现短期盐峰又有长期积累现象,存在盐渍化趋势,并主要受干旱枯水因素影响。三峡调蓄的影响程度有待进一步研究。提出应有针对性地采取合理灌排措施和Na质盐碱土改良措施。
In order to study the soil salinization along the river and seacoast in the Yangtze River estuary in autumn after the Three-Gorge Reservoir impounded water for two years, soil samples were collected there and soil salt composition tested. With the aid of a statistic software, principal component analysis was conducted of types and characters of the saline soils therein, and cluster analysis of the soil salt profile types. Results show that in the two years after the Three- Gorge Reservoir began to impounded water the main type of soil in the Yangtze River estuary in autumn is saline fluvoaquic soil, of which the cation composition is dominated with Na^+ , whereas the anion composition with SO4^2- which is a little more than Cl^-. Salt accumulation occurs mainly in the upper layers of the soil profiles and displays both short-term peaks and a long-term accumulating trend. The aggravation of soil salinization was mainly caused because of the dry year. The extent of impacts of the Three-Gorge Reservoir needed further study. On such a basis, the author calls for site-specific rational irrigation/drainage practices and measures to ameliorate Na^+ type saline soil.